But what took place in the skies and on the ground was rivaled by the little-known espionage beneath the waves. Spies didn't just wear trench coats; they also wore Navy blue.

The U.S. sailors silently cruised the icy waters off the Soviet Union, tapping military communications cables and snatching everything from warheads to sunken Russian subs.

"We forget that there was a lot to be gained from the ocean floor," says Norman Polmar, a naval analyst and author, who is not surprised by the American public's ignorance of the sub-based spies. "Like all things underwater, the people don't see them as much."

Or hear from them. There is more than one reason why those who served on submarines were members of the "Silent Service."

Now a new book is bringing these secret submariners to the surface. "Blind Man's Bluff: The Untold Story of American Submarine Espionage," by Sherry Sontag and Christopher Drew, the most comprehensive look at the work of these intrepid sailors. The title is borrowed from an admiral's comment that "submarining has always been a game of blind man's bluff."

The book tells how U.S. submarines were used to tap the Soviet communications cables in the Sea of Okhotsk in the Far East and in the Barents Sea, the Arctic waters that sheltered a major submarine base. What they achieved were among the best-kept secrets of Cold War intelligence, the authors say.

The idea for the espionage came from an unlikely spot: the banks of the Mississippi River. Capt. James Bradley, director of undersea warfare at the Office of Naval Intelligence, recalled as a young boy in the 1930s cruising the Mississippi to escape the oppressive summer heat of St. Louis. He remembered seeing signs on the river banks: "Cable Crossing. Do Not Anchor."

Would the Russians have similar warnings? Bradley wondered. The USS Halibut slipped into the Sea of Okhotsk in 1971 with its periscope up and spent more than a week searching. The crew finally spotted a Russian sign on the beach -- alerting ships to a cable crossing.

Divers were dispatched from the sub and attached a 3-foot-long device that included a recorder filled with rolls of tape. It provided a treasure trove of Soviet voice and data transmissions. The National Security Agency at Fort Meade decoded and analyzed the tapes, which included conversations between Soviet sub commanders and top military officials.

Another sub, the USS Parche, tapped the cable in the Barents Sea in 1984, picking up "a detailed look" into the Soviet navy's nuclear strategy. CIA and NSA officials termed the information -- "the big casino" and "the crown jewels."

The subs stole not only conversations but also Soviet military hardware. Cruise-missile parts splintered deep in the ocean were grabbed and analyzed by the Defense Department.

Also, the spy subs snapped pictures of a Golf II Soviet submarine that sank three miles below the Pacific. The Halibut took 22,000 photos of the Golf that were collectively code-named "Velvet Fist" and offered a wealth of technical secrets.

"It gave us hard data about what their systems could do," says a former high-ranking Defense Department official. "I think it was very useful. It was important."

Polmar also notes that because many agents were betrayed during the Cold War by Kim Philby and other British intelligence officials turned Russian spies, the work of the submarines proved even more important.

The tapping in the Sea of Okhotsk ended in 1982 when the Soviets fished out the tap pod marked "Property of the United States Government." (It now sits in a Moscow museum.)

A Navy official wrote a report that year, suspecting a spy was behind the Russian find. Three years later, Ronald W. Pelton, a former NSA cryptologist, was arrested in Annapolis. Facing bankruptcy, Pelton decided on a side job with the Russians -- and sold out the Okhotsk tap for $35,000.

Still, the Barents cable continued to provide intelligence through the end of the Cold War.

Even the Okhotsk betrayal helped the Americans. "When [the Soviets] found out how effectively we were tailing them and nTC listening to their calls, it just drove them crazy and helped accelerate their collapse," says the former top Pentagon official. "It gave them an inferiority complex [about] how good our technology was."

Although the book is a celebration of the sailors, their ingenuity and valor, the U.S. Navy and others in the Pentagon are grumbling about the release of stories still classified.

"The Navy does not endorse or officially support this book," says a statement put out last month by the service. "Personnel should be reminded that there is no change to existing policies prohibiting the release of classified information."

The Navy even crafted a response to help active-duty and retired sailors questioned about "Blind Man's Bluff."

"The following statement should be used. Quote. 'As a matter of policy we do not discuss specific submarine operations in the interests of national security,' " says the official response.

Most are adhering to the Navy directive. "I have no comment," says retired Adm. Robert Long, who once headed the Navy's sub program and pushed for the Parche. Pressed for a comment, the Annapolis resident says cryptically: "Submarines have in the past and continue to play a critical part in protecting the national security of the United States."

Stansfield Turner, a retired admiral and former CIA director who headed the spy agency during some of the most spectacular spy sub work, also begs off.

Retired Adm. Charles R. Larson, the former Naval Academy superintendent, skippered the Halibut on its last tapping run in Okhotsk. And while his effort led to untold thousands of captured Soviet phone calls, he declined to return a reporter's call.

"I'm reading it myself, as a matter of fact," says John H. Maurer Jr., the former captain of the Parche, referring to the book. "Fascinating."

But Maurer, a 1962 academy graduate, also won't comment. He quickly mentions the federal law -- 18 U.S. Code 798 -- that prohibits the release of any information relating to signals intelligence.

And the retired skipper says there's another reason for silence: His wife, Carol, would be angry. He refused to answer her questions all those years. Maurer says he's also refusing his wife's request to underline the book's best parts with a yellow marker.

The former top defense official and Polmar say it's time for the Navy to lift the veil on its Cold War secrets.

"There's no reason anymore to keep a lot of that classified," says Polmar. "The Russians know we did it."